This research proposal is designed to investigate the mechanisms involved in the absorption of fat soluble vitamins, using vitamin K as a springboard. The specific transport mechanisms and kinetics will be identified using rat small bowel gut sacs. Factors which may enhance and/or diminish the rate of transport will be looked for. Possible regional differences in the rate of absorption in the various segments of the small bowel will be looked for. Using gut sac techniques, as well as perfusion experiments, the contribution of the large bowel to fat soluble vitamin absorption will be investigated. The effects of biliary and pancreatic diversions on fat soluble vitamin absorption in experimental animals will be investigated. Fat soluble vitamin absorption will be investigated in normal human volunteers as well as in patients with bowel diseases resulting in fat malabsorption, or in patients with resection of portions of the small and large bowel.